A diplomatic crisis bogging down Ottawa and New Delhi highlights Canada's lack of "seriousness" on national security as foreign countries interfere on the North American nation's soil, according to several experts.

Indo-Canadian relations, already tense, deteriorated further earlier this week when Canada raised the possible involvement of the Indian government in the June killing of a Sikh separatist near Vancouver.

"The crisis with India is a huge, huge slip-up," said Charles-Philippe David, a strategic and diplomatic studies professor at the University of Quebec in Montreal.

He told AFP that Ottawa has been receiving warning signals for a "long time" about foreign interference on its territory.

The global context, "transformed in recent years and accelerated by Ukraine," is forcing Canada, according to David, to "choose camps and take tougher and firmer positions."

But so far the country has been in a state of "dormancy," manifested in a lack of ambition, resources and leadership, he said.

"We must treat international relations and foreign policy with much more seriousness than we have done for a long time," insists David.

One of his peers at the University of Ottawa points out that Canada has not reviewed its foreign policy in the last "one or two generations."

"That is a failure of our government, regardless of which political party was in power. We need a defense policy that is appropriate," public and international affairs professor John Packer told AFP.

He believes that a growing number of autocracies are exerting influence on Canadian soil.

"Canadians have felt safe (surrounded by) three oceans and a friendly neighbor to the south," he said. "But that's long gone. Those oceans are no longer impenetrable."

'Naive' Canada

Tensions with India prove, according to Packer, that "the world has changed and we have to get up to speed with that."